Leads represent the electrical link between an implantable medical device (IMD) and a subject's cardiac tissue, which is to be excited or stored. A lead may include a single or multiple conductors that are connected to an electrode or an electrode assembly at a lead intermediate portion or lead distal end. A connector is included at a lead terminal end to form an electrical connection between the electrode or electrode assembly and the IMD. The connector typically includes lead terminal contacts, such as a lead terminal pin or at least one lead terminal ring.
To implant the lead with the subject, the lead is often fed intravenously toward the subject's heart. To facilitate the difficult travel of the lead through the subject, lead and their corresponding elements, such as the lead terminal contacts, are being designed smaller. This smaller size makes access to lead elements inherently more difficult for an implanting physician. Also influencing a reduction in the size of the lead elements, specifically the lead terminal contacts, is the advent of multipolar inline lead terminal technology.
Once the lead is implanted within the subject and the electrode or electrode assembly is positioned at a desired location within, on, or about the subject's heart, it is often desirable to provide some method for securing the electrode or electrode assembly at that precise location. Mechanical fixation devices may be used to firmly anchor the electrode or electrode assembly at the desired location. One type of mechanical fixation device used is a fixation helix, which anchors the lead distal end. The fixation helix is typically extended and screwed into cardiac tissue by applying a torque to the other end of the conductor that the fixation helix is engaged with or by rotating the lead itself.
After anchoring the lead distal end, the implanting physician will often establish an electrical connection between at least one electrode and a test or stimulation system, such as a pacing system analyzer (PSA). To make this electrical connection, a clip(s) (e.g., an alligator clip) coupled to one end of an analyzer conductor(s) (e.g., cable) is typically attached directly to the lead terminal pin and the at least one lead terminal ring. This direct contact between the clip(s) and the lead may permanently damage the lead at the point(s) of attachment. For instance, the attachment or subsequent detachment of the clip may severely scratch (e.g., groove) the lead. Additionally, the tighter axial spacing of the electrical contacts (e.g. lead terminal rings or lead terminal pin), which is a byproduct of multipolar inline lead terminal technology, may result in the clip attachment bridging between two or more electrical contacts thereby impeding testing or stimulation.
Accordingly, what is needed is an apparatus which prevents damage to a lead and facilitates installation of the lead in many ways, thereby saving the implanting physician valuable time and effort.